Science STAAR Review

What is the difference between a physical change and a chemical change?

• A physical change alters the form of a substance without changing its identity, while a chemical change results in the formation of new substances.

• A physical change involves the creation of new substances, while a chemical change does not alter the substance's form.

• A physical change is reversible, while a chemical change is always irreversible.

• A physical change occurs at the molecular level, while a chemical change occurs only at the atomic level.

Which of the following is NOT a mixture: a glass of lemonade, a salad, or a pure element?

• A glass of lemonade

• A salad

• A pure element

• A fruit smoothie

What type of circuit has only one path for current to flow?

• A parallel circuit.

• A series circuit.

• A complex circuit.

• A closed circuit.

What is an example of a defense mechanism in animals?

• A skunk using its spray.

• A rabbit running away from a predator.

• A bird building a nest.

• A fish swimming in schools.

What is the primary function of a decomposer in an ecosystem?

• To produce energy through photosynthesis.

• To break down dead organic matter and recycle nutrients.

• To compete with producers for sunlight.

• To provide shelter for herbivores.

What is the term for a mixture where the components are evenly distributed?

• Homogeneous mixture

• Heterogeneous mixture

• Colloidal mixture

• Suspension

What is the term for the maximum population size that an environment can sustain?

• Carrying capacity

• Population density

• Ecological footprint

• Biological limit

What is the role of producers in an ecosystem?

• Producers create energy through photosynthesis.

• Producers consume other organisms for energy.

• Producers decompose organic matter.

• Producers regulate the population of consumers.

What is the process by which plants convert sunlight into energy?

• Respiration

• Photosynthesis

• Transpiration

• Fermentation

What is the role of consumers in an ecosystem?

• Consumers produce energy through photosynthesis.

• Consumers obtain energy by eating other organisms.

• Consumers decompose organic matter into nutrients.

• Consumers are the primary producers in an ecosystem.